The 212-page confidential report has indicted the three firms on several counts.

The report says the discoms not just manipulated consumer figures, but also purchased power at higher rates, inflated costs and suppressed revenue.

The CAG report also put the three companies in dock for transacting with other private firms without issuing tenders and for favouring group companies.

However, inflation of regulatory assets (RA) was the action that hurt the consumer most.

RA is any previously-incurred losses which, if allowed by the regulator, can be recovered from consumers.

"The RA of three discoms which stood approved as on March 31, 2013, were Rs 13,657.87 crore. However, audit findings contained in various chapters of this report indicate that the RA of the three discoms were inflated by at least Rs 7956.91 crore," states the CAG report, as per the daily.

If the recommendations made in the report are implemented, power consumers in Delhi could see their monthly bills come down.

"Analysis shows that inefficiencies get loaded to the cost of power at several stages from the source till it reaches the consumer — that is, in generation, transmission and distribution losses — making the retail price significantly higher. There is a scope for reducing the cost of power by reducing inefficiencies at various stages," the audit report says.

The report also raised doubts over the conduct of Delhi Electricity Regulatory Commission (DERC) and government nominees on the board of the three power suppliers.

The Aam Aadmi Party government had ordered a special CAG audit of the power companies alleging the discoms were overcharging consumers in Delhi using unfair means.